The 1974-1978 Moto Guzzi 750, 850, 1000 V-Twins DIY repair manual by Haynes covers the following motorcycle models:
Book Excerpt: 1974-1978 Moto Guzzi 750-S, 750-S3, 850-T, 850 T3, V1000, LeMans Repair Manual
- Moto Guzzi 750S (748cc) UK 1974
- Moto Guzzi 750S3 (748cc) UK, 1975-1976
- Moto Guzzi 850T (844cc) USA, 1975-1977
- Moto Guzzi 850T (844cc) UK 1974-1976
- Moto Guzzi 850T3 (844cc) UK and USA 1975-1978
- Moto Guzzi LeMans (844cc) UK, 1976-1978
- Moto Guzzi V1000 Convert (949cc) UK and USA, 1975-1978
ENGINE REASSEMBLY | REPLACING THE CAMSHAFT, OIL PUMP AND TIMING THE VALVES
FRAME AND FORKS
- Place the timing chain tensioner arm in position in the casing with the distance piece on each bolt between the arm and the casing. Tighten the bolts lightly.
- Lubricate the camshaft journal and insert the camshaft into the crankcase. Fit the endplate and tighten the three screws.
- Position the oil pump in the casing and fit the four retaining bolts. The oil pump must be fitted so that the drive spindle is offset from the line of the crankshaft and camshaft. Tighten the four bolts evenly to 3 kg m (22ft lbs), checking by rotation of the driveshaft that the pump gears do not bind.
- Insert the drive pin into the eccentrically drilled hole in the camshaft and replace the Woodruff keys into the keyways of the other two shafts.
Arrange the camshaft, crankshaft and oil pump sprockets on the workbench and fit the cam chain as it would be fitted on the engine.
The timing mark on the camshaft sprocket should be aligned roughly with that of the crankshaft sprocket. Lift the complete assembly up and engage each sprocket with its respective shaft, holding the two sprockets in alignment.
- Rotate the camshaft and crankshaft until the keys align with the keyways in the sprockets. Push the sprockets fully home on the shafts. The index marks on the two upper sprockets must be in alignment. One or two attempts may have to be made to ensure the timing is accurate.
- Replace the sprocket retaining nuts and washers. The tab washer on the special crankshaft nut is inordinately difficult to bend up after the nut has been tightened, due to lack of space. It is worth bending up the extreme ends of the ears before refitting, to aid final securing of the nut.
- As when loosening the nuts, rotation of the shafts may be prevented by passing a close fitting bar through the small end eye, resting on wooden blocks across the crankcase mouth.
- Push the chain tensioner across towards the middle of the casing until all slack has been taken up. Hold the tensioner arm in the chosen position and tighten the two bolts. Rotate the crankshaft a number of times and check that the chain does not become over tight at any point.
If this occurs, slacken the tensioner bolts and readjust at the tightest point. Secure the two bolts by means of their locking plates.
- Place a new gasket on the timing chest mating surface and refit the cover. On V-1000 models the hexagonal drive piece fitted into the end of the camshaft must engage correctly with the converter oil pump drive boss.
Fit the cover bolts and tighten them evenly, in a diagonal sequence, to avoid distortion.
FINAL DRIVESHAFT | EXAMINATION AND RENOVATION
- The final driveshaft may be removed for inspection after detaching the swinging arm and bevel drive box, as described in the previous Section.
- If wear in the universal joint is evident, the complete assembly must be renewed. On all but V-1000 models the driveshaft is a separate item to the joint and need only be renewed if the coupling splines at either end are badly worn.
- Check the fit of the driveshaft ball bearing inner race with the inner boss on the universal joint. The boss should be a tight drive fit in the race. Looseness at this point is not an uncommon occurrence.The only remedy is to renew one or both of the components. The use of a locking fluid is unlikely to provide a reliable remedy unless the clearance is very small.The bearing is retained within the swinging arm fork by a large internal circlip. Removal of the circlip may prove difficult unless a pair of long handled circlip pliers is available. The bearing may be drifted out, using a long punch inserted from the bevel drive end.
- When refitting the driveshaft, grease the internal and external splines of the coupling sleeve and shaft with graphite grease.
Haynes manuals can be a tremendous help when restoring your classic Moto Guzzi motorcycle.Subject: 1974, 1975, 1976, 1977, 1978 Moto Guzzi 750-S, 750-S3, 850-T, 850 T3, V1000, LeMans service, maintenance, repair. ISBN-10: 0856963399 | ISBN-13: 9780856963391 | Haynes 339